Since Zorin Lite updated to 12.2 Dropbox seems to start correctly about half the time. Actually it seems to work OK but the tray icon doesn’t render or function properly.
Below is how I managed to resolve this as best as I could. The icon no longer has the green tick when it is up to date but I think that is do do with Dropbox and not Zorin/Xfce desktop!!!
Open the file manager and go to your /home folder, right click an empty area and choose Create Document > Text File, name it dropbox.sh then right click it and choose Open With Text Editor.
Paste in the code below,
sleep 5s && dbus-launch dropbox start &
And Click Save.
Now right click the file and choose Properties, go to the permission tab at the top and put a check in the Program: Allow this file to run as a program check box.
Next click the Zorin button on the panel and go to Settings then Session and Startup and choose the middle tab at the top called Application Autostart, click the Add button, you may have to scroll down to find it.
Name: Dropbox Workaround or whatever you like.
Description: Make Dropbox Work or whatever you like or leave empty.
Command: click the up arrow and browse to your home and click on the dropbox.sh file, click Open the click OK.
The sleep 15s command in the code to give the automatic self regenerating dropbox autostart entry time to run before stopping it, if your dropbox icon appears in the panel in within a few seconds of login you could make it 5 or 10 seconds or 20 or 30 seconds for slower systems.
Thus far this is working as good as can be expected for me so just wait and see